Sentry PurrScriptions Cat & Kitten Squeeze-On Flea & Tick Control, has anyone used this before?

Sentry PurrScriptions Cat & Kitten Squeeze-On Flea & Tick Control
what would you say are the chances that this would work for a cat that is about 2 weeks old? we have only found one flea on her, so we’re not sure if we should get this or frontline (http://www.petco.com/product/12685/FRONTLINE-Plus-for-Cats.aspx). even though frontline has better reviews it is SOOO expensive! please help us, thank you!

shes like 7-8 weeks old darla xD